O trabalho desenvolvido teve como foco dois sistemas químicos integrados: células solares sensibilizadas por corantes, Dye-Cells®, e fotossensores baseados em compostos de rênio(I). Novos compostos de rutênio(II) foram preparados, caracterizados e investigados como corantes sensibilizadores. Os resultados obtidos com as células solares sensibilizadas pelo cis-[(H3BCN)2Ru(dcbH2)2], H3BCN- = cianoboroidreto, dcbH2 = ácido-4,4\'-dicarboxílico-2,2\'-bipiridina, são: Jsc = 8,0 mA.cm-2, Voc = 0,66 V, Pmax = 2,7 mA.cm-2 e ff = 0,51. Esse dispositivo atingiu eficiência de conversão de fótons incidentes em corrente de até 23%. Os compostos cis-[Ru(dobH2)2(L)2]0/2+, dobH2 = ácido-4,4\'diidroxâmico-2,2\'-bipiridina e L = Cl-, H2O ou NCS-, foram preparados usando o ácido hidroxâmico como um novo grupo de ancoramento. Os desempenhos das células solares são: cis-[(Cl)2Ru(dobH2)2]: Jsc = 4,6 mA.cm-2, Voc = 0,60 V, Pmax = 1,4 mW.cm-2, ff = 0,51; cis-[Ru(dobH2)2(H2O)2]2+: Jsc = 4,4 mA.cm-2, Voc = 0,61 V, Pmax = 1,6 mW.cm-2, ff = 0,59; cis-[(SCN)2Ru(dobH2)2]: Jsc = 4,6 mA.cm-2, Voc = 0,71 V, Pmax = 1,5 mW.cm-2, ff = 0,46. A similaridade dos valores de Jsc sugere que o grupo de ancoramento pode estar limitando o processo de injeção de carga na banda de condução do semicondutor. Frutos distintos dos já investigados são utilizados como fontes de antocianinas empregadas como sensibilizadores. Esses corantes naturais são capazes de adsorver à superfície do semicondutor e realizar a conversão de luz em eletricidade. Foram determinados eficiência de conversão de fóton incidente em corrente de até 19% e valores de Jsc = 7,2 mA.cm-2, Voc = 0,65 V, Pmax = 2,0 mW.cm-2 e ff = 0,55. O segundo sistema químico integrado investigado baseia-se em fotossensores com fac-[Re(CO)3(NN)(stpy)]+, NN = 2,2\'-bipiridina, bpy, 4,4\'-dimetil-2,2\'-bipiridina, Me2bpy, ou dipirido[3,2-a:2\',3\'-c]fenazina, dppz, stpy = trans ou cis-4-estirilpiridina. A reação de isomerização trans-cis do ligante coordenado pode ser acompanhada de duas formas distintas por espectrofotometria e por ressonância magnética nuclear, 1H RMN. Os rendimentos quânticos aparentes, Φap, determinados para irradiação em 404 nm, por espectrofotometria, são: fac-[Re(CO)3(bpy)(trans-stpy)]+ Φap = 0,19 ± 0,02; fac-[Re(CO)3(Me2bpy)(trans-stpy)]+ Φap = 0,18 ± 0,02; fac-[Re(CO)3(dppz)(trans-stpy)]+ Φap = 0,30 ± 0,03. Enquanto os valores reais determinados por 1H RMN, Φreal, são: fac-[Re(CO)3(bpy)(trans-stpy)]+ Φreal = 0,48 ± 0,03; fac-[Re(CO)3(Me2bpy)(trans-stpy)]+ Φreal = 0,31 ± 0,07; fac-[Re(CO)3(dppz)(trans-stpy)]+ Φreal = 0,48 ± 0,06. Os valores determinados por 1H RMN são reais uma vez que os sinais do produto e do reagente são detectados em regiões distintas, o que não acontece no acompanhamento por espectrofotometria. A isomerização trans-cis do composto fac-[Re(CO)3(bpy)(trans-stpy)]+ também é observada em poli(metacrilato) de metila, que foi o meio rígido utilizado visando o desenvolvimento de dispositivos. O isômero fac-[Re(CO)3(bpy)(cis-stpy)]+ é luminescente e a sua emissão é investigada em diferentes meios analisando os deslocamentos hipsocrômicos com o aumento da rigidez do meio. / The focus of this work is on two chemical integrated systems: dye-sensitized solar cells, Dye-Cells®, and photosensors based on rhenium(I) compounds. Novel ruthenium(II) compounds were synthesized, characterized and investigated as dye-sensitizers. The results of solar cells sensitized by cis-[(H3BCN)2Ru(dcbH2)2], H3BCN- = cyanoborohydride, dcbH2 = acid-4,4\'-dicarboxylic-2,2\'-bipyridine, are: Jsc = 8.0 mA.cm-2, Voc = 0.66 V, Pmax = 2.7 mA.cm-2 and ff = 0.51. Incident photon-to-current efficiency of up to 23% is achieved by this device. The cis-[Ru(dobH2)2(L)2]0/2+ compounds, dobH2 = acid-4,4\'-dihydroxamic-2,2\'-bipyridine, L = Cl-, H2O or NCS-, were synthesized using hydroxamic acid as a new anchoring group. The performance of these dye-sensitized solar cells are: cis-[(Cl)2Ru(dobH2)2]: Jsc = 4.6 mA.cm-2, Voc = 0.60 V, Pmax = 1.4 mW.cm-2, ff = 0.51; cis-[Ru(dobH2)2(H2O)2]2+: Jsc = 4.4 mA.cm-2, Voc = 0.61 V, Pmax = 1.6 mW.cm-2, ff = 0.59; cis-[(SCN)2Ru(dobH2)2]: Jsc = 4.6 mA.cm-2, Voc = 0.71 V, Pmax = 1.5 mW.cm-2, ff = 0.46. The similarity between Jsc values suggests that the anchoring group is limiting the electron injection into the semiconductor conducting band. Anthocyanins of several fruits were employed as sensitizers. These natural dyes are capable of adsorbing onto the semiconductor surface and promote the light-to-electricity conversion. Incident photon-to-current efficiency of up to 19% and values Jsc = 7.2 mA.cm-2, Voc = 0.65 V, Pmax = 2.0 mW.cm-2, ff = 0.55 were determined. The second chemical integrated system investigated is based on photosensors using fac-[Re(CO)3(NN)(stpy)]+, NN = 2,2\'-bipyridine, bpy, 4,4\'-dimethyl-2,2\'-bipyridine, Me2 bpy, or dipyrido[3,2-a:2\',3\'-c]phenazine, dppz, stpy = trans or cis-4-styrylpyridine. The trans-cis isomerization of the coordinated ligand is followed by two distinct ways, spectrophotometry and nuclear magnetic resonance, 1H NMR. The apparent quantum yields, fiap, determined for irradiation at 404 nm by spectrophotometry are: fac-[Re(CO)3(bpy)(trans-stpy)]+ Φap = 0.19 ± 0.02; fac-[Re(CO)3(Me2bpy)(trans-stpy)]+ Φap = 0.18 ± 0.02; fac-[Re(CO)3(dppz)(trans-stpy)]+ Φap = 0.30 ± 0.03. The real values, Φreal, determined by 1H NMR, are: fac-[Re(CO)3(bpy)(trans-stpy)]+ Φreal = 0.48 ± 0.03; fac-[Re(CO)3(Me2bpy)(trans-stpy)]+ Φreal = 0.31 ± 0.07; fac-[Re(CO)3(dppz)(trans-stpy)]+ Φreal = 0.48 ± 0.06. The values determined by 1H NMR are real since the signals of the product and of the reactant are detected in distinct regions, which does not occur for the spectrophotometric method. The trans-cis isomerization of the compound fac-[Re(CO)3(bpy)(trans-stpy)]+ is also observed in poly(methyl)methacrilate, which was the rigid medium employed aiming the development of devices. The fac-[Re(CO)3(bpy)(cis-stpy)]+ isomer is luminescent and its emission is investigated in different media analyzing the hypsochromic shifts increasing the rigidity of the medium.

Nos travaux s’inscrivent dans le contexte global de la transition énergétique et de l’émergence des micro-réseaux, et de leur capacité, à terme, d’intégrer la production distribuée d’énergie tout en assurant la stabilité et la qualité du service. Parmi les technologies émergentes, les procédés Power-To-Gaz et en particulier le Power-to-Methane que nous étudions ici (production de CH4 à partir de l’électricité, en passant par H2 et CO2) ont l’avantage : d’absorber le surplus de production électrique, de récupérer et valoriser les émissions de CO2, et d’offrir des capacités de stockage importantes et de longue durée.Notre problématique porte sur la modélisation et la simulation d’un système PtM avec comme objectif d’assurer la continuité d’alimentation en CH4, ainsi que la sécurité du système en fonctionnement.Dans un premier temps nous effectuons le choix de technologies adaptées afin de déterminer la structure d’un système PtM avant de dimensionner ce système. Nous nous appuyons sur la modélisation REM (Représentation Energétique Macroscopique) pour intégrer les comportements physiques des équipements du système en régime stationnaire, mais également en régime transitoire, en prenant en compte des phases comme : le démarrage, le préchauffage…, et ainsi simuler le fonctionnement de ce système.Dans un second temps, nous développons une stratégie de gestion d’énergie multiniveaux afin de garantir le bon fonctionnement des équipements et du système dans sa globalité. Nous choisissons de la mettre en œuvre à travers la proposition d’un système multi-agents (SMA) et nous modélisons chacun des agents. Nous implémentons partiellement ce SMA et nous le simulons en connexion avec le modèle REM du système PtM pour montrer la faisabilité de notre approche. / Our work is concerned with energy transition and the emergence of micro-grids and their ability to integrate distributed power generation while at the same time ensure stability and service quality. Among the emerging technologies, the Power to Gas process and in particular the Power to Methane process which we are addressing here (production of CH4 from electricity, via H2 and CO2), have the advantage of absorbing surplus of electricity production, recovering CO2 emissions, as well as offering significant and long-term storage capacity.Our concern was in relation to the modeling and simulation of a PtM system with the objective of ensuring the continuity of CH4 supply and ensuring the safety of the system in operation.First, we chose the appropriate technologies to determine the structure of a PtM system before sizing this system. We utilised the REM modeling (Energetic Macroscopic Representation) to integrate the physical behaviors of the equipment of the system in a steady state, and in a transient state, taking into account phases like starting, preheating…, and ultimately the simulation of the operation system.In the second phase, we developed a multilevel energy management strategy to ensure the proper working order of each piece of equipment and of the global system. We chose to implement it through a multi-agent system (MAS) and we modeled each one of the agents. We partially implemented the MAS and simulated it with the REM model of the PtM system to show the feasibility of our approach.

Maintaining a constant supply of clean drinking water is among the most pressing global challenges in our time. About one-third of the population is affected by the water scarcity and it can only get worse with climate change, rapid industrialization, and the population growth. Even though nearly 70 percent of the planet is covered by water, the consumable freshwater content is only 2.5 percent of it. Unfortunately, the accessible portion of it is only 1 percent. Even so, most of the freshwater bodies are choked with pollution. Considering the vast availability of saline water on the planet and the increasing wastewater generation, seawater desalination, and wastewater treatment and recycling seem to have the potential to address current water-related issues. Therefore, it is necessary to find efficient techniques for seawater desalination and wastewater treatment. The use of nanostructured materials for these applications is becoming a popular approach due to the unique chemical and physical properties they possess compared to bulk materials Solar energy is the cleanest and most abundant renewable natural resource available. Materials for solar photothermal energy conversion are highly sought after for their cost savings, clean environment, and broad utility in providing water heating and/or steam for many applications including domestic water heating and solar-driven desalination. Extensive research efforts have been made to develop efficient solar absorbers with characteristics such as low weight, low thermal conductivity, broad solar absorption and porosity to be able to float on water to provide more efficient and cost-effective solar steam generation systems. Metal NPs have been proposed to take advantage of the high efficiency of the photothermal energy conversion associated with surface plasmon resonance absorption. Nanostructured carbon-based materials such as graphene oxide, carbon nanotubes, carbonized biomass are also in use due to their excellent photothermal energy conversion ability over the range of the visible and near infra-red region of the electromagnetic spectrum. In this dissertation, five projects based on the utility of nanostructured materials for desalination, photocatalysis and water treatment will be discussed. The first three projects involve the fabrication and design of plasmonic and carbon-based photothermal materials for applications in solar steam generation, water desalination, and wastewater treatment. In the fourth project, a unique shape of ZnO nanostructure was synthesized for photodegradation of organic dyes in industrial wastewater. The final project demonstrates the shape-controlled synthesis of iron carbide nanostructures and composite materials of aminated graphene oxide for the removal of Cr(VI) from wastewater.

D. Tech. Electrical Engineering. / Discusses the objectives of thesis in terms of : 1. To formulate and integrate models for the wind-turbine, induction generator, PV array, battery, supercapacitor, and power electronic converters in a form suitable for studying the dynamic behaviour of the microgrid; 2. To develop an online optimisation algorithm and use it to optimise local control algorithms for PV array, energy storage system, and the doubly fed induction generator. 3. To formulate an efficient power sharing strategy between battery and supercapacitor. 4. To implement an overall control system which sets the power reference for the energy storage system and ensures that the requested power demand is supplied to the grid.

A detailed understanding of natural photosynthesis provides inspiration for the development of sustainable and renewable energy sources, i.e. a technology that is capable of converting solar energy directly into chemical fuels. This concept is called artificial photosynthesis. The work described in this thesis contains contributions to the development of artificial photosynthesis in two separate areas. The first one relates to light harvesting with a focus on the question of how electronic properties of photosensitizers can be tuned to allow for efficient photo-induced electron transfer processes. The study is based on a series of bis(tridentate)ruthenium(II) polypyridyl complexes, the geometric properties of which make them highly appealing for the construction of linear donor-photosensitizer-acceptor arrangements for efficient vectorial photo-induced electron transfer reactions. The chromophores possess remarkably long lived 3MLCT excited states and it is shown that their excited-state oxidation strength can be altered by variations of the ligand scaffold over a remarkably large range of 900 mV. The second area of relevance to natural and artificial photosynthesis that is discussed in this thesis relates to the coupled movement of protons and electrons. The delicate interplay between these two charged particles regulates thermodynamic and kinetic aspects in many key elementary steps of natural photosynthesis, and further studies are needed to fully understand this concept. The studies are based on redox active phenols with intramolecular hydrogen bonds to quinolines. The compounds thus bear a strong resemblance to the tyrosine/histidine couple in photosystem II, i.e. the water-plastoquinone oxidoreductase enzyme in photosynthesis. The design of the biomimetic models is such that the distance between the proton donor and acceptor is varied, enabling studies on the effect the proton transfer distance has on the rate of proton-coupled electron transfer reactions. The results of the studies have implications for the development of artificial photosynthesis, in particular in connection with redox leveling, charge accumulation, as well as electron and proton transfer. In addition to these two contributions, the excited-state dynamics of the intramolecular hydrogen-bonded phenols was investigated, thereby revealing design principles for technological applications based on excited-state intramolecular proton transfer and photoinduced tautomerization.

Photon upconversion by sensitized triplet–triplet annihilation (UC-STTA) is a photophysical process that facilitates the conversion of two low-energy photons into a single high-energy photon. A low-energy photon is absorbed by a sensitizer molecule that produces a triplet excited state which is transferred to an emitter molecule. When two emitter triplet states encounter each other, TTA can take place to produce a singlet excited state which decays by emission of a high-energy (upconverted) photon. While traditional single-threshold dye-sensitized solar cells (DSSCs) have a maximum efficiency limit of ca. 30%, it has been predicted theoretically that implementation of UC-STTA in DSSCs could increase that efficiency to more than 40%. A possible way to implement UC-STTA into DSSCs, would be to replace the standard sensi- tized nanostructured TiO2 photoanodes by upconverting ones loaded with emitter molecules. Following TTA, the excited emitter molecule would be quenched by injection of a high-energy electron into the conduction band of the TiO2. To explore the practical aspects of this strategy for a highly efficient DSSC, in this thesis UC-STTA is studied in model systems based on nanostructured ZrO2 films. These ZrO2 films are a good proxy for the TiO2 films used in DSSCs, and allow for relatively easy optimization and study of UC-STTA by allowing measurements of the upconverted photons without the complications of electron injection into the film. Herein it is experimentally proven that UC-STTA is viable on nanostructured metal oxide films under non-coherent irradiation with intensities comparable to sunlight. Two different system architectures are studied, differing in the position of the molecular components involved in the UC-STTA mechanism. Both architectures have the emitter molecules adsorbed onto the ZrO2 surface, but the sensitizers are positioned either in solution around the nanostructure, or co-adsorbed with the emitters onto the ZrO2 surface. A set of challenges in the study and optimization of the UC-STTA process is identified for each type of system. Proposals are also given for how to further improve the understanding and UC-STTA optimization of these systems toward application in DSSCs to overcome the present solar energy conversion efficiency limit.

Radial gas turbines engines have established prominence in the field of small turbomachinery because of their simplicity, relatively high performance and installation features. Thus they have been used in a variety of applications such as generator sets, small auxiliary power units (APu), air conditioning of aircraft cabins and hybrid electric vehicles turbines. The current research describes the design, manufacturing, construction and testing a radial type small gas turbine. The aim was to design and build the engine to drive directly a high-speed permanent magnet alternator running at 60000 rpmand developing a maximum of 60 W. This direct coupling arrangement produces a portable, light, compact, reliable and environment friendly power generator. These features make the generator set very attractive to use in many applications including emergency power generation for hospitals, in areas of natural disasters such as floods and earthquakes, in remote areas that cannot be served from the national grid, oil rigs, and in confined places of limited spaces. It is important to recognize that the design of the main components, that is, the inward flow radial UFR turbines, the centrifugal compressor and the combustion chamber involve consideration of aero-dynamics, thermodynamics, fluid mechanics, stress analysis, vibration analysis, selection of bearings, selection of suitable materials and the requirements for manufacturing. These considerations are all inter-linked and a procedure has been followed to reach an optimum design. This research was divided into three phases: phase I dealt with the complete design of the inward radial turbine, the centrifugal compressor, the power transmission shaft, the selection of combustion chamber and the bearing housing including the selection of bearings. Phase 2 dealt with mechanical consideration of the rotating components that is stress, thermal and vibration analyses of the turbine rotor, the impeller and the rotating shaft, respectively. Also it dealt with the selection of a suitable fuel and oil lubrication systems and a suitable starting system. Phase 3 dealt with the manufacturing of the gas turbine components, balancing the rotating components, assembling the engine and finally commissioning and then testing the engine. The current work in this thesis has put the light on a new design methodology on determining the optimum principal dimensions of the rotor and the impeller. This method, also, has defined the optimum number of blades and the axial length of the rotor and the impeller. Mathematical models linking the performance parameters and the design variables for the turbine and the compressor have been developed to assist in carrying out parametric studies to study the influence of the design parameters on the performance and on each other. Also, a new graphical matching procedure has been developed for the gas turbine components. This technique can serve as a valuable tool to determine the operating range and the engine running line. Furthermore, it would decide whether the gas turbine engine operates in a region of satisfactory compressor and turbine efficiencies.

This dissertation presents the development of electrically-powered, lamination-based microactuators for the realization of large arrays of high impulse and short duration micro-jets with potential applications in the field of micro-electro-mechanical systems (MEMS). Microactuators offer unique control opportunities by converting the input electrical or chemical energy stored in a propellant into useful mechanical energy. This small and precise control obtained can potentially be applied towards aerodynamic control and transdermal drug delivery applications. This thesis discusses the development of both chemical and physical microactuators and characterizes their performance with focus towards the feasibility of using them for a specific application. The development of electrically powered microactuators starts by fabricating an array of radially firing microactuators using lamination-based micro fabrication techniques that potentially enable batch fabrication at low cost. The microactuators developed in this thesis consist of three main parts: a micro chamber in which the propellant is stored; two electrode structures through which electrical energy is supplied to the propellant; and a micro nozzle through which the propellant or released gases from the propellant are expanded as a jet. The fabricated actuators are then integrated with MEMS-process-compatible propellants and optimized to produce rapid ignition of the propellant and generate a fluidic jet. This rapid ignition is achieved either by making the propellant itself conductive, thus, passing an electric current directly through the propellant; or by discharging an arc across the propellant by placing it between two closely spaced electrodes. The first concept is demonstrated with chemical microactuators for the application of projectile maneuvering and the second concept is demonstrated with physical microactuators for transdermal drug delivery application. For both the actuators, the propellant integrated microactuators are characterized for performance in terms of impulse delivered, thrust generated and duration of the jet. The experimentally achieved results are validated by comparing with results from theoretical modeling. Finally, the feasibility of using chemical microactuators for maneuvering the path of a 25 mm projectile spinning at 500 Hz is discussed and the feasibility of applying the physical microactuators for increasing skin's permeability to drug analog molecules is studied.

Thesis (M.S.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 108-114). Also available on the World Wide Web.

The thesis contains essential information on the methods and possibilities of using water power. The first part deals with the history of water works, and introduction to basic physics of energy conversion. Further research is made available sources of information on the history, technology, power generation and design of hydropower Lipno I and II, with mention of unrealized project pumping plant Lipno III. The conclusion evaluates the defined objectives and creates a short summary.